SHOKT-RANCE PROPAGATION IN DEEP WATER 



205 



Figure 10. Records showing multiple path effects. Source: No. 8 cap at depth 100 feet and at ranges indicated. 

 Hydrophone at depth 54 feet. Date: Apr. 2, 1942. Gain of the recording system was sometimes changed between shots. 



duced considerable crossing of the ray paths.' The 

 630-yd oscillogram has very much the form one would 

 expect if there were two ray paths leading from cap 

 to hydrophone. That for 800 yd suggests a number 

 of ray paths, but the arrivals are less sharp. It is diffi- 



cult to correlate these features in detail with the 

 calculated ray diagram, however, and there appear 

 to be variations which make it hard to pick out sys- 

 tematic trends in the characters of the oscillograms 

 as the range is gradually increased or decreased. 



